Wrapped insulation-piercing connector

ABSTRACT

This connector consists of a shell, an insulation-piercing type insert, a leaf spring therebetween, and a plastic film bonded to the shell. A spring force on the insert maintains long term contact of the piercing tangs with the conductors. A crimping tool is disclosed having a die with a main-slot wire guide for all splice types. Wires to be severed are led to a branching slot where, during splicing, the shell edge severs conductors therein. Useful for telephone gauge conductors, this connector system requires no insulation stripback or special handling skills.

United States Patent Stanley Casimlr Antas lrvington;

George Thomas Genneken, Whippany; Donald Tolman Smith, PiscatawayTownship, Middlesex, all of NJ.

Aug. 25, 1970 Nov. 16, 1971 Bell Telephone Laboratories IncorporatedMurray Hill, NJ.

lnventors Appl. No. Filed Patented Assignee WRAPPED INSULATION-PIERCINGCONNECTOR 9 Claims, 28 Drawing Figs.

us. 01 174/84 c,

29/628, 174/90, 339/97 c. 339/276 R 1111. cr 1102 15/08 Field of Search174/34 c,

90, 94 R; 339/95, 97, 276 R, 276 T; 29/628 [56] References Cited UNITEDSTATES PATENTS 3,242,256 3/1966 Jugle. 174/84 C 3,303,266 2/1967Thompson. 174/84 C 3,514,522 5/1970 Kuo 174/90X Primary Examiner-Darrell L. Clay Attorneys-R. J. Guenther and Edwin B. Cave I /V YPATENTEDNUV 16 ISTI SHEET 2 0F 7 PATENTEBuuv 16 new 3.621.117

saw 6 [1F 7 PATENTEnunv 16 ml SHEET 7 OF 7 FIG. 2/

FIG. 22

FIG. 23

FIG. 26

WRAPPED INSULATION-PIERCING CONNECTOR FIELD OF THE INVENTION Thisinvention relates to the joining of electrical conductors in the 19- to26-gauge range; and specifically concerns the making of solderlessmetal-to-metal insulated joints in such conductors.

BACKGROUND OF THE INVENTION Numerous expedients exist for the quickconnection of one insulated conductor to another. Among such devices inwidespread use are those described in U.S. Pat. Nos. 3,064,072;3,436,820; and 3,0l2,2l9.

Notwithstanding the general acceptance of the foregoing items, there isyet a need for a splicing system which makes the bridging of conductorseasier than at present; and the joining of large-pair-count cable afaster process.

Accordingly, the following are all objects of the present invention:

to simplify conductor insertion in a solderless crimp-type electricalconnector;

to obtain better contact performance between the contacting element andthe conductor to be joined;

to permit bridging without the cutting of the through conductor;

to achieve a connector design which permits automatic conductortrimming;

to speed up the bridging of conductors in the field; and

to expedite the joining of large-pair-count cable.

SUMMARY OF THE INVENTION These objects and others are achieved by theinsulationpiercing connector of the present invention. The connectorconsists of a shell, a piercing-type insert, a leaf spring therebetween,and a plastic film advantageously bonded to the shell. Connections areeffected by a portable tool comprising a die with a main-slot wire guidefor all splice types. In the splicing process, the edge of the shellsevers conductors which are led up through a branching slot.

The spring force on the insert maintains long term contact of thepiercing tangs with the conductors. The insert advantageously iscomprised of a spring temper phosphor bronze material which allows theformation of strong tangs. Convolutions at each end of the insertprovide mechanical gripping of the conductors to prevent pullout.

The spring is compressed during the crimping, thus applying for the lifeof the connection a positive compressive force to the insert. A tendencyexhibited in many previous designs of tangs to retreat from theconductor, because of a natural tendency for the insert to spring backand because of a long term creep mechanism, is thus avoided.

The shell protects the insert from external disturbance, whiletransmitting forces between the insert and the spring. A fairlysubstantial force is generated by the spring in conjunction with anannealed brass shell, which constitutes a preferred inventiveembodiment.

The design accommodates a large range of conductor combinations withoutrequiring conductor insulation removal. Thus, connections may be madebetween two or three conductors ranging in gauge from 19 to 26.

The invention and its further objects, features, and advantages will bereadily apprehended from a reading of the description to follow of anillustrative embodiment.

DESCRIPTION OF THE DRAWING prior to crimp- FIG. 4a is a top view of thecrimping die jaws of FIG. 4;

FIG. 4b is a frontal perspective view of the die jaws depicted in FIG.4;

FIGS. 5 through 17 are various side sectional views of the connector ofFIG. 2 showing connector bending and crimping sequences occuring in thecrimping die;

FIG. 18 is a top perspective view of an alternate embodiment of the bodyand spring members of FIG. 1;

FIG. 19 is a top perspective view of an alternate embodiment of thespring and insert members of FIG. I; and

FIGS. 20 through 26 are schematic diagrams of various wire connectionsthat may be made by the present invention.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT CONNECTORCONFIGURATION FIG. 1 shows the components of a connector 5 in explodedview prior to their being crimped. The shell, designated 10, is anelongated generally J-shaped member made of annealed brass, by a processof stamping. The walls l1, 12 of shell 10 each include perforations 13,I4 and 15, 16 respectively, symmetrically placed inwardly of the wallends. On each of the two ends ofthe walls 11, 12 are inwardly extendingtabs 17, 18 and 19, 20 respectively. The wall 11 is taller than wall 12,and includes one or more edge extensions such as extensions 2|, 22, 23.To provide a firm cutting edge, the upper edge of wall 11 is hardened,as by inward compression, creating a groove 24 which extends from thewall end to edge extension 23; and a like groove 25 from the other endof wall 11 to the edge extension 21.

In the embodiment shown in FIG. I, the spring member designated 30advantageously comprises an elongated strip made of spring temperphosphor bronze and comprising relatively flat end portions 31, 32 and acentral outwardly protruding bow portion 33. Spring 30 also includesalong its sides. arms 34, 35, which locate in the perforations 13, 14respectively, of shell 10; and arms 36, 37 which locate in theperforations l3, 14 respectively, of shell 10; and arms 36, 37 whichlocate in the perforations I5, 16 of shell 10.

The insert designated 40 is likewise made from spring temper phosphorbronze by the process of stamping. Viewed edge-on, insert 40 is.I-shaped and consists of a floor 41, a major wall 42, and oppositethereto minor wall 43. Insert 40 is substantially coextensive in lengthwith shell 10. Wall 42 includes cutout portions 44, 45 at its ends, thecutouts 44, 45 engaging tabs 18, 17 respectively ofwall ll of shell 10,as seen in FIG. 2.

In the embodiment shown in FIG. I, insert 40 consists of a field 46inwardly protruding tangs centrally located in floor 41; and a field 47of inwardly protruding tangs centrally located in the wall 42. The tangsof the tang fields 46, 47 are advantageously punched out, with spacingsto ensure that any conductor in the range 19 to 26 gauge is contacted.Outwardly of the tang field 46, on either side of floor 41, are formed aseries of transverse ribs 48, 49, 50 at one end and 51, 52, 53 at theother end. Each two adjacent such ribs are provided with spaces betweenthem. Wall 42 of insert 40 includes inwardly extending ribs 54,55, 56 atone end and 57, 58, 59 at the other end. The ribs 54-59 likewise aretransverse of wall 42 and advantageously commence at the edge 60 of wall42, ending short of the bend line 61 between wall 42 and floor 41. Theregion between the end of each rib 54-59 and the bend line 61 isprovided with raised nipples 62-67, respectively situated opposite theends of ribs 54-59. The nipples 62-67 prevent wires from escaping fromthe tangs, and importantly also promote formation of a second bend line61a to achieve parallelism between the floor 41 and the wall 42 afterforming, as seen in FIG. 11.

As seen in FIG. 1, the floor ribs 48-50 and the wall ribs 54-56 arestaggered in spacing so that when the insert 40 is folded during theeffecting of a connection, these ribs shall interleave. Similarly, theribs 51-53 are spaced with respect to the ribs 57-59 so thatinterleaving shall occur when the insert 40 is folded.

Advantageously, the edge of major wall 42 of insert 40 is provided withthree cutouts 68, 69, 70; and the minor wall 43 of insert 40 is providedwith cutouts 71, 72, 73. As seen in FIGS. 10 and 11 during the effectingof a connection and as the insert 40 is folded, the edge extensions 21,22, 23 of the wall 11 of shell 10 are caused to engage the insertcutouts 68-70 and also the insert cutouts 71, 72, 73. This further locksthe insert with respect to the shell.

A plastic film designated 80 is bonded to the shell 10 in the mannershown in FIG. 2, to provide electrical insulation for the metallic partsof the assembly. Plastic film 80 is generally .I-shaped to conform tothe shape of shell 10, but wider than shell 10, and its wall 82 islonger than the corresponding wall 12 of shell 10 as shown in FIG. 2.Plastic film 80 advantageously is corrugated longitudinally to provideboth a degree of rigidity and extensibility in the transverse direction.Advantageously, the material from which film 80 is made is a polyesterhaving good mechanical and electric properties as well as environmentalstability. The bonding agent is, for example, a polyester adhesivehaving long term adherence under severe environmental conditions.

An alternate embodiment ofthe shell 10 is shown in FIG. 18 in which thespring member is formed directly thereinto. In FIG. 18, certain numeralsused in FIG. 1 denote parts which correspond identically to those shownfor the shell 10 in FIG. I. This alternate shell of FIG. 18, designatedshell 10a, differs from that shown in FIG. 1 principally in that thereis formed directly into the base 26 of shell 10a an inwardly extendingbow 33a which corresponds in structure and function to the bow 33 ofspring 30. The shell 10a combines the structure and function ofshell 10with the spring 30 shown in FIG. 1.

FIG. 19 shows an alternate embodiment of the insert 40, designatedinsert 40a. Here again, certain numerals denote parts of insert 400which are identical to those designated with like numerals for insert 40in FIG. I. The difference between the inserts 40 and 40a is that thecentral tang fields 46, 47 as well as the ribs 54-59 and 48-53 arereplaced by a series of bowed or raised areas which have interleavingtransverse serrated edges, these being designated serrated edges 90through 97 located in wall 42, and 98 through 105 located in floor 41.The advantage of insert 40a is that a spring such as spring 30 is notnecessary as resilience is inherent in this bow shape; and thatfurthermore, the transverse serrated edges 90 through 97 can be moreprecisely controlled as to shape and sharpness. The latter permits amore precise control of insulation penetration and contact with theunderlying conductor.

Crimping Die FIGS. 4, 4a, and 4b depict a crimping die designated 110and consisting of a jaw 111 and a die 112. .law 111 is movable in thedirections shown by arrow 113. The jaw 111 and die 112 advantageouslyare mounted on opposing arms of either a handtool or a bench tool(neither shown). Jaw 111 includes arms 114, 115 extending outwardlyfrom, and then parallel to, the interior working surface of the jaw lll,defining slots 116, 117 in which the connector assembly is mounted. Themounting of an assembled connector 5 is achieved by sliding thecorrugated plastic film edges through the slots 116, 117 to achieve alight gripping. The body ofjaw 111 and its working face against whichthe floor of connector 5 seats provides a firm bed with which to forcethe crimping action.

Die 112 consists of a body 120 mounted between a pair of side members121, 122. Each side member includes a mouth defined between the topsurfaces 123, 124 and front edges 125, 126, respectively. This mouthleads to a slot 127 in side 121 and a slot 128 in side 122. Springs 129,130 are mounted across the slots 127, 128 and are bowed upwardly to madenormal contact with the surface 123, 124, respectively. Conductorchambers 133, 134 are formed in the region behind the springs 129, 130in which, as shown in FIG. 4, the conductors 131, 132 are grippinglyaccommodated.

The body 120 includes a nest 140, and a pair of cutting slots 141, 142.Above the nest 140 is a guide surface 143 with notched indentations 144,145, 146 to accommodate the edge extensions 21 22, 23 ofshell in aguiding manner.

Cutting slots I41 and 142 include bevels 147, 148 that serve as acutting edge for a conductor such as 131 to be bridged. in a manner tobe described.

Steps in Forming the Connection The sectional view of FIG. 5 showsconductors I31, 132 suspended across the wire nest and being approachedby a connector assembly 5 which is being forced by the jaw 111.Conductor 131 has been led through the cutting slot 142 preparatory toits severance. The assembled connector 5 guides into position with itstop wall 11 being guided by the top surface 149 of the body 120, and itsbottom wall 12 being guided by the bottom guide surface 150 of body 120.It is seen in FIG. 5 that the leading lip 80a of plastic film 80 movesin advance of the wall 12. In FIG. 6, the wall 11 leading edge 11a movesagainst the conductor 131 insulation, driving it against the cuttingedge of bevel 148. FIG. 7 shows the completion of the severance ofconductor 131 in a shearing motion between the bevel 148 and the sharpleading edge 11a. The conductors 131, 132 are now positioned forenvelopment by the connector 5.

FIGS. 8 through 11 portray the further sequence of crimping takenthrough a side section that illustrates the guided folding of edgeextensions 21 through 23. In FIG. 8, edge extension 21 is channeled innotched indentation 146, best seen in FIG. 4b. The leading lip 80a offilm 80 previously been folded back to the position shown in FIG. 8, byits riding along the curved surface of nest 140 as seen in FIG. 7. Thus,upon being bent in the notched indentation 146 as shown in FIG. 8, edgeextension 21 (and its companions 22 and 23) capture the film leading lip80a, folding it downwardly onto the interior surface of wall 12.

At about the point depicted in FIG. 8, the leading edge 11a encountersthe guide surface 143 depicted in FIG. 4b. Further crimping forms thewall 11 into the bend depicted in FIG. 9 as the wall 11 rides over theextended edge 151 between the nest 140 and the guide face 143. The bendline 61a is seen in FIG. 8 to be materializing, and furthered in FIG. 9.

By virtue of the bending occasioned in wall 1] by the extended edge 151and the top surface 149, the wall 11 assumes the bend depicted in FIG.10. Here, edge extension 21 by virtue of previous bends is guided intocutout 68 ofinsert 40. The leading edge 11a approaches contact with thenow completely overlapped leading lip 80a of plastic film 80. Theconductors 131, 132 are about to be gripped by the entire series of ribs48 through 53 and 54 through 59, which are shown in FIG. I. The leadingedge 12a of wall 12 has been forced into conformity with the curvedsurface of nest 140, and is in substantial overlapping relation with theedge Ila. Finally, as depicted in FIG. 11, the crimp is completed.

FIG. 12 is a section taken lengthwise of the wires which shows the ribs48 through 59 gripping the conductors I31 and 132, the latter not shown.

FIGS. 13 through 17 depict the bending sequence taken through a sectionthat includes the tang field 46, 47. The section is taken so as toinclude an edge extension 21 its notched indentation forming groove 146.FIG. 14 depicts the tang field 47 as clearing the conductors 131, 132 asthe crimping proceeds. Finally, as seen in FIGS. 15, 16, and 17, thewires 131, 132 are enveloped and ultimately their insulation pierced bythe tang fields 46, 47. The spring 30 is finally fully compressed asshown in FIG. 17 to provide lasting contact between the tang fields andthe conductors as they are compressed between the spring and wall 11 ofshell 10.

FIGS. 20 through'26 illustrate different types of connections that maybe made with the described wrapped insulation piercing connector 5. InFIG. 20, a bridge conductor is connected to a through conductor 161. InFIG. 21, two bridge conductors 162, 163 are connected to a throughconductor 164. In FIG. 22, the through conductor 165 is connected tobridge conductors 166, 167 both of which exit from one side of theconnector 5.

In FIG. 23 two joined conductors 168, 169 enter from a single side ofthe connector 5; and in FIG. 24, conductors 170 and 171 are connectedwithin the connector 5. FIG. 25 demonstrates that three conductors 172,173, 174 all leading into one side of the connector 5 may be thereinconnected. FIG. 26 shows the case of connecting two conductors 176, 177coming into one side of the connector to a third conductor 178 leadingfrom the other side.

Numerous other connection schemes are, of course, envisionable, theforegoing being merely illustrative instances.

Various modifications and changes may be made to the inventiveembodiment described, and it is understood that all such changes areembraced in the spirit of the invention as defined in the scope of theclaims to follow.

What is claimed is: l. A connector for splicing telephone conductors,comprising;

a J-shaped outer shell; a leaf spring loosely mounted on said shell atits base interior; and a metallic insert for receiving and engagingconductors, said insert disposed atop said spring and having a zone ofinsulation-piercing tangs, the closing of said shell effecting also afull closing of said insert around said conductors and also forming aroof against which said spring compresses said insert. 2. A connectorfor splicing insulated electrical conductors, comprising:

an elongated outer shell comprising a first wall, a shorter second wall,and a base portion therebetween; spring means disposed on said baseportion between said walls and having a springy central region;compliant metal insert means for receiving conductors to be joined, saidinsert means disposed in said shell atop said spring means and having amajor wall, a minor wall and a floor portion therebetween, the majorwall and floor portion both having means located in their respectivecentral regions for mechanically piercing said electrical insulation andfor engaging the underlying conductor; means on either side of therespective said central regions for securely gripping the insulation ofsaid conductor; means for effecting a joint between said shell firstwall and the edge portions of said major wall and said minor wall upon afolding together of said shell and said insert edge portions duringcrimping; and a plastic film enveloping said shell exterior. 3. Aconnector in accordance with claim 2, further comprising means formounting said spring means on said base comprising at least oneextension on each edge of said spring and a like number of cavities ineach said shell first and second walls for engaging of said extensions.

4. A connector in accordance with claim 2, wherein said mechanicalpiercing means comprises opposing tang fields in the central regions ofsaid major wall and said floor portions. and wherein said gripping meanscomprises plural protruding ribs spaced transversely on either side ofeach said tang field, said ribs being staggered to interleave with oneanother upon folding of said major wall over said floor portion duringcrimpmg.

5. A connector in accordance with claim 4, wherein the boundary betweensaid major wall and said floor portion of said insert constitutes afirst bend line and said insert further having a plurality of protrudingnipples located beyond the interior end of each rib on said major wall,the region between said plural nipples and said major wall plural ribsconstituting a zone for effecting a second bend line during folding ofsaid insert means.

6. A connector in accordance with claim 5, further comprising means formounting said insert on said base, comprising an upwardly extending tabat each end of said first wall and of said second wall of said shell,for engaging the four corners of said insert means.

7. A connector in accordance with claim 6, wherein said plastic filmoverlaps said shell at the ends thereof, said film further having plurallongitudinal corru ations, said film being affixed to san shellexterior, one film e ge extending substantially beyond the edge of saidshell second wall for overlapping of same on completion of said folding.

8. A connector in accordance with claim 2, wherein said joint-effectingmeans comprises at least one edge extension of said shell first wall,and corresponding notches in the edges of said insert major and minorwalls respectively, for engaging said first wall extensions.

9. A connector for splicing insulated electrical conductors, comprising:

a J-shaped outer shell having a resilient bow-shaped base;

a metallic insert for receiving and engaging conductors, said insertdisposed within said shell and having insulationpiercing tangs, theclosing of said shell effecting also a full closing of said insertaround said conductors and also forming a roof against which said insertis compressed.

1. A connector for splicing telephone conductors, comprising; a J-shapedouter shell; a leaf spring loosely mounted on said shell at its baseinterior; and a metallic insert for receiving and engaging conductors,said insert disposed atop said spring and having a zone ofinsulation-piercing tangs, the closing of said shell effecting also afull closing of said insert around said conductors and also forming aroof against which said spring compresses said insert.
 2. A connectorfor splicing insulated electrical conductors, comprising: an elongatedouter shell comprising a first wall, a shorter second wall, and a baseportion therebetween; spring means disposed on said base portion betweensaid walls and having a springy central region; compliant metal insertmeans for receiving conductors to be joined, said insert means disposedin said shell atop said spring means and having a major wall, a minorwall and a floor portion therebetween, the major wall and floor portionboth having means located in their respective central regions formechanically piercing said electrical insulation and for engaging theunderlying conductor; means on either side of the respective saidcentral regions for securely gripping the insulation of said conductor;means for effecting a joint between said shell first wall and the edgeportions of said major wall and said minor wall upon a folding togetherof said shell and said insert edge portions during crimping; and aplastic film plastic film enveloping said shell exterior.
 3. A connectorin accordance with claim 2, further comprising means for mounting saidspring means on said base comprising at least one extension on each edgeof said spring and a like number of cavities in each said shell firstand second walls for engaging of said extensions.
 4. A connector inaccordance with claim 2, wherein said mechanical piercing meanscomprises opposing tang fields in the central regions of said major walland said floor portions, and wherein said gripping means comprisesplural protruding ribs spaced transversely on either side of each saidtang field, said ribs being staggered to interleave with one anotherupon folding of said major wall over said floor portion during crimping.5. A connector in accordance with claim 4, wherein the boundary betweensaid major wall and said floor portion of said insert constitutes afirst bend line and said insert further having a plurality of protrudingnipples located beyond the interior end of each rib on said major wall,the region between said plural nipples and said major wall plural ribsconstituting a zone for effecting a second bend line during folding ofsaid insert means.
 6. A connector in accordance with claim 5, furthercomprising means for mounting said insert on said base, comprising anupwardly extending tab at each end of said first wall and of said secondwall of said shell, for engaging the four corners of said insert means.7. A connector in accordance with claim 6, wherein said plastic filmoverlaps said shell at the ends thereof, said film further having plurallongitudinal corrugations, said film being affixed to said shellexterior, one film edge extending substantially beyond the edge of saidshell second wall for overlapping of same on completion of said folding.8. A connector in accordance with claim 2, wherein said joint-effectingmeans comprises at least one edge extension of said shell first wall,and corresponding notches in the edges of said insert major and minorwalls respectively, for engaging said first wall extensions.
 9. Aconnector for splicing insulated electrical conductors, comprising: aJ-shaped outer shell having a resilient bow-shaped base; a metallicinsert for receiving and engaging conductors, said insert disposedwithin said shell and having insulation-piercing tangs, the closing ofsaid shell effecting also a full closing of said insert around saidconductors and also forming a roof against which said insert iscompressed.